The art of extracting power from moving water is old and includes numerous and different types of paddle wheels designed to extract power from moving streams and rivers, those having cup-like paddles which are operated by the gravitational force of water supplied from above, and modern hydroelectric turbines wherein high pressure water is utilized to drive the turbine structure. The water wheels of this prior art are conventionally supported by a central axle which is directly coupled to a power take off shaft, requiring the use of extremely heavy duty bearings in the power take off mechanism. There is a need for a water wheel assembly which utilizes both the pressure generated from an elevated water supply and the force of gravity on one quarter of the water wheel, and is supported other than by the central axle so that the power take-off linkage is separated from the support bearings.